I doubt Apple would have started the trend if they didn't have an expectation of sticking to it (for at least a little while anyways, to test the waters). And there was a comment by one of their developers that really made sense to me in the end...having two devices per year like this never leaves someone with the idea of going to the store to get "the old iPhone" once a new one is released. I guess they approached it with the logic that you're always going to have the late to the party consumer, and instead of having their mind in the idea of only being able to afford the "old" device, they can now have a brand NEW device, at the lower cost.

I'd personally rather have Apple continue with one, single device per year and put all the focus into that...but they've yet to let me down with a release, so I'll hold off any real cynical approach to this idea until one does (which will hopefully never happen).